Two new high resolution data sets of global urbanization have been released through NASA's Socioeconomic Data and Applications Center (SEDAC).The Global Man-made Impervious Surface (GMIS) and the Human Built-up And Settlement Extent (HBASE) companion data sets are the first global, 30m spatial resolution data sets of their kind using the 2010 Global Land Survey (GLS) free Landsat archive to map global man-made impervious surfaces and urban extent in unprecedented detail.

Data Sources:

This study was funded by NASA's Land Cover Land Use Change (LCLUC) Program. The base Landsat data are from the Global Land Survey (GLS) data for the target period 2010, processed to surface reflectance. The data sets have been generated from a massive training set (+27M Pixels) produced from unclassified commercial satellite data via the National Geospatial-Intelligence Agency's (NGA) NextView contract. The Hseg Image segmentation tools used extensively here were developed at NASA GSFC by Co-I Tilton.

: With over half of the world's population living in urban areas today, the mapping and monitoring of urbanization is critical to understanding associated changes and their potential impacts on humans and Earth systems alike. While urban areas still represent a small proportion of the Earth's land surface, their impacts on hydrology, carbon, ecosystem services and energy/emissions, are felt from local to global scales.
As we look to a future with a rapidly urbanizing planet it is imperative to develop the tools with which we can accurately measure and monitor urban expansion and its characteristics. These are central to a better understanding of the impact and consequences of this change, and the impacts and consequences of a changing climate on future cities and settlements.
The availability of high resolution, free satellite imagery at multiple epochs from the GLS Landsat archive, and the NGA commercial satellite archive, provide great opportunities to map global man-made surfaces and extent in unprecedented detail. Future data from Landsat 9/10 and the Sentinels will further set the stage for high resolution monitoring of urbanization well into the future. New data sets in the vertical domain will also allow us to study the 3-D structure of the urban fabric.